I also recommend taking pictures of the following:
-> Left side.
-> Right side.
-> Closeup of any marking or engraving (including the serial number).
-> The octave key mechanism -- but not so much that I can't see the actual octave key, itself. That's the thing you put your left thumb on.
-> A tonehole ("valve") or two, particularly of the ones on the bell, if you're talking about a saxophone.
-> Anything you feel is unique or interesting about your horn.
-> The neck, barrel, bocal or headjoint of the instrument.
-> Picture of any major damage that you see.
-> Low C keyguard, if it's a saxophone. That's the key you'd hit with the pinky of your right hand.
I do not want or need close-ups of interesting-looking rust patterns or funky mold growing on your horn.